awk move select fields to match file prefix in two directories

In the awk below I am trying to use the file1 as a match to file2 . In file2 the contents of $5,&6,and $7 (always tab-delimited) and are copied to the output under the header Quality metrics. The below executes but the output is empty. I have added comments to help and show my thinking. Thank you :).

$5 = Total_Targets with value under it that can be a decimal or integer
$6 = Targets_less_than250x with value under it that can be a decimal or integer
$7 = Percent_more_than250x with value under it that can be a decimal or integer

file1 (123_Last-First_250x.txt)

Position    Gene    Type    Reads   Total_Targets   Targets_less_than250x   Percent_more_than250x
chr4:55141051   PDGFRA  NOCALL  13  2353    1   99.9575

file2 (123_Last-First_oca.txt)

Controls:
4 expression controls detected

desired output (123_Last-First_oncomine.txt)

Quality metrics:
Total_Targets   Targets_less_than250x   Percent_more_than250x
2353    1   99.9575
Controls:
4 expression controls detected

awk

portion in bold grabs $5,$6,$7 in file1 and stores it in array A and prints it in file2 '
portion in teal adds the header to the output

awk 'FNR==NR{A[$5,$6,$7]=$0;next}$1 in A' OFS=\'t'  123_Last-First_250x.txt 123_Last-First_oca.txt | awk 'NR>1{print "Quality metrics:"}' > output